Mipmaps implementation

examples/16_textured_scene.py

@@ -1,6 +1,6 @@
 # Example 16: Textured raytracing
 #
-# This time we render a triangle and scene
+# This time we render a triangle and sphere
 
 from pyrt.light import PointLight
 from pyrt.scene import *
@@ -38,11 +38,11 @@
              Vertex(position=(0, 1, 5), texcoord=(1, 0)),
              Vertex(position=(5, 1, 0), texcoord=(1, 1)),
              material=
-             TextureMaterial(texturepath='tex16.png'))
+             TextureMaterial(texturepath=['tex16.png']))
 
 s = Sphere(center=Vec3(0, -3, 0), radius=1,
            material=
-           TextureMaterial(texturepath='tex16.png'))
+           TextureMaterial(texturepath=['tex16.png']))
 
 # Add triangle and sphere to the scene:
 scene.add(t)

examples/17_mipmaps.py

@@ -0,0 +1,67 @@
+# Example 17: Textured raytracing
+#
+# This time we render a triangle and scene with mipmaps
+# Used textures contain funny digits
+# Digit corresponds to level of detalization
+
+from pyrt.light import PointLight
+from pyrt.scene import *
+from pyrt.material.texturematerial import TextureMaterial
+from pyrt.camera import PerspectiveCamera
+from pyrt.renderer import SimpleRT
+
+from pyrt.renderer import RGBImage
+from pyrt.math import Vec3
+from pyrt.geometry import Triangle, Vertex
+import moviepy.editor as mpy
+
+
+def make_frame(t):
+    w = 320
+    h = 240
+
+    # Create a camera with width, height and field of view:
+    camera = PerspectiveCamera(w, h, 60)
+
+    # Set View matrix of camera: define where to look at
+    camera.setView(Vec3(0, -t - 10, 0), Vec3(0, 0, 0), Vec3(0, 0, 1))
+
+    #  Create view-projection matrix (right to left)
+    vp =  camera.projection * camera.view
+
+    # Create a scene
+    scene = Scene()
+
+    # Add a light to the scene
+    scene.addLight(PointLight(Vec3(0, -2, 0)))
+
+    # Create a triangle
+    t1 = Triangle(Vertex(position=(-5, -4, 5), texcoord=(0, 0)),
+                 Vertex(position=(5, -4, 5), texcoord=(1, 0)),
+                 Vertex(position=(5, -4, -5), texcoord=(1, 1)),
+                 material=
+                 TextureMaterial(texturepath=['tex17-1.png', 'tex17-2.png']))
+
+    t2 = Triangle(Vertex(position=(-5, -4, 5), texcoord=(0, 0)),
+                 Vertex(position=(5, -4, -5), texcoord=(1, 1)),
+                 Vertex(position=(-5,-4, -5), texcoord=(0, 1)),
+                 material=
+                 TextureMaterial(texturepath=['tex17-1.png', 'tex17-2.png']))
+
+    # Add triangle and sphere to the scene:
+    scene.add(t1)
+    scene.add(t2)
+
+    # Now tell the scene which camera we use
+    scene.setCamera(camera)
+
+    # Create a raytracer using "SimpleRT"
+    engine = SimpleRT()
+
+    # Render the scene:
+    image = engine.render(scene)
+    return image.data
+
+
+clip = mpy.VideoClip(make_frame, duration=7)
+clip.write_gif("17.gif",fps=1)

pyrt/camera/camera.py

@@ -46,3 +46,11 @@ def getMatrix(self) -> Mat4:
         :return:
         """
         pass
+
+    @abstractmethod
+    def getSize(self) -> tuple:
+        """
+        Returns the resolution tuple (w, h)
+        :return:
+        """
+        pass

pyrt/camera/orthographiccamera.py

@@ -27,3 +27,6 @@ def __init__(self, width=512, height=512):
     def primaryRay(self, x: float, y: float) -> Ray:
         r = Ray(Vec3(x, y, 0.), self.direction)
         return r
+
+    def getSize(self) -> tuple:
+        return self.width, self.height

pyrt/camera/perspectivecamera.py

@@ -89,7 +89,6 @@ def setProjection(self, fov: float, width: int, height: int, znear: float, zfar:
         self.matrix = self.projection * self.view
         self.matrixinv = inverse4(self.matrix)
 
-
     def getMatrix(self) -> Mat4:
         """
         Returns the view-projection matrix
@@ -98,3 +97,5 @@ def getMatrix(self) -> Mat4:
         """
         return self.matrix
 
+    def getSize(self) -> tuple:
+        return self.width, self.height

pyrt/material/texturematerial.py

@@ -7,19 +7,22 @@
 from .material import Material
 from ..math import Vec3, Ray, HitRecord, dot3, reflect3, normalize3, clamp3
 from ..camera import Camera
+from math import log2, floor
 
 
 class TextureMaterial(Material):
 
     """Texture Material Class"""
 
     def __init__(self, color: Vec3 = Vec3(1.,1.,1.), shininess: float = 10.0, reflectivity: float = 0.0, refraction: float = 1.0,
-                 texturepath: str = ''):
+                 texturepath: list = None):
         Material.__init__(self, color, shininess, reflectivity, refraction)
-        self.texture = None if len(texturepath) == 0 else Texture(texturepath)
+        self.texture = None \
+            if texturepath is None \
+            else {i: Texture(texturepath[i]) for i in range(len(texturepath))}
 
-    def setTexture(self, texture: Texture):
-        self.texture = texture
+    def addTexture(self, lod: int, texture: Texture):
+        self.texture.update({lod: texture})
 
     def shade(self, camera: Camera, ray: Ray, hitrecord: HitRecord,  lights: list) -> Vec3:
         """
@@ -29,7 +32,13 @@ def shade(self, camera: Camera, ray: Ray, hitrecord: HitRecord,  lights: list) -
         """
         colorsum = Vec3(0.,0.,0.)
 
-        texcolor = self.texture.color(hitrecord.texcoord)
+        if self.texture is None or len(self.texture) == 0:
+            texcolor = self.color
+        else:
+            size = camera.getSize();
+            resolution = size[0] * size[1];
+            lod = floor(log2((hitrecord.point - camera.position).length() / resolution) + 14)
+            texcolor = self.texture[max(0, min(lod, len(self.texture) - 1))].color(hitrecord.texcoord)
 
         if len(lights) > 0:
             for light in lights:

pyrt/renderer/simplert.py

@@ -17,6 +17,7 @@ def __init__(self, shadow=False, iterations=1):
         Renderer.__init__(self, "Simple Raytracer")
         self.shadow = shadow
         self.iterations = iterations
+
         if self.shadow:
             print("# Shadow Enabled")
         if self.iterations>1: